Signalling Power Supplies
|Publication Date:||1 August 2006|
This guidance applies to new works and modifications to signalling power supply distribution installations as defined by Railway Group Standards. The associated specification NR/SP/ELP/27243 - Specification for signalling power supplies should be read in conjunction with this document.
The extent to which NR/SP/ELP/27243 should be applied to signalling power distribution systems is dependent on whether it is a new or existing installation. There is currently no requirement to bring existing installations into compliance with the requirements in Railway Group Standards. However, installations commissioned or modified when the Electricity at Work Regulations (EAWR) came into force should already be compliant with the requirements of EAWR.
Design, commissioning, test and inspection of new installations must be carried out in accordance with BS7671. Guidance on the process of design is provided within NR/GN/ELP/00015 - Signalling power supply design.
It is permissible for Projects that have formally completed GRIP level 4 before 4 September 2006 to continue to comply with relevant Network Rail standards that were current when GRIP level 4 was achieved. However it is recommended that all planned work is reviewed against NR/SP/ELP/27243 to identify any requirements that can be practicably implemented.
If the requirements of NR/SP/ELP/27243 cannot be achieved, a formal derogation to the standard is required which describes the means by which compliance with the EAWR Regulations are being achieved. The derogation must have the support of the Territory E&P Engineer.
This document supports NR/SP/ELP/27243: Specification for Signalling Power Supplies. This document provides guidance on the requirements of its counterpart standard.
Signalling power supply installations are required to comply with the requirements of the Electricity at Work Regulations 1989 (EAWR). GI/RT7017 mandates 'as far as reasonably practicable' the application of BS7671 to signalling power distribution installations as a means of achieving compliance with the EAWR Regulations. However, the requirements of other Standards such as Railway Group, Network Rail Company, British, European and International for equipment installed in the Railway environment must also considered, and where appropriate, applied.